DE4401284C2 - Use of diabase or basalt for soil stabilization - Google Patents

Description

The invention is directed to the use of powdered diabase or basalt rock in a batch with others, including silicate ones Ground stabilization materials.

For soil consolidation, e.g. B. for the consolidation of a subsoil or Road substructure such that the ground of construction vehicles so solidified different compaction methods can be used became known. For example, in the book "Additional Techni cal regulations and guidelines for earthworks in road construction, com mentor Dr. Floss, Kirschbaum Verlag, 1979 "Soil consolidation process described with the aid of binders, calcium oxide or calcium umhydroxide play an important role. For example, the Zuga be of quicklime a solidification through formation of calcium carbonate and calcium silicates, in addition by quenching the Quicklime water is bound, so that through this and through occurring heat of reaction the water content of the soil is reduced, so that driving on such prepared ground soon after Ein Bringing the lime is possible.

The known methods using lime are very effective sam, however, lime is a comparatively expensive material, so that the  this cost factor, especially for large-scale construction projects lasting noticeable.

Proceeding from this, the object of the invention is a similar one surface stabilization effect as with the conventional methods achieve, but at least partially cheaper available mate rialien should be usable, preferably such materials that soft other processes occur anyway as waste products, so that with their Recovery is also linked to a recycling effect.

This object is achieved in that powdery, magmatic Diabase or basalt rock, mixed with others, including silicate ones Materials used for soil consolidation, being used, too the igneous rock powder applied to solidifying soils and in the surface worked in or in underground hollows brings and preferably solidified under pressure.

To achieve the above object, a mixture is also included send a share of calcium or calcium hydroxide containing material the igneous diabase or basalt rock.

It has been found that when, for example, diabase is used, the he not only takes on the role of a filler, but similarly to that Lime creates an active hardening effect.

For example, when examining untreated loess on the one hand soil and on the other hand with a proportion of lime and diabase Loess soils can be seen under the scanning electron microscope that as a result of  geological Ginese the pure loess more than glacial Aeolian sediment or less clearly recognizable has a single grain system, which also has larger pores when mechanically compressed. A bond of individual grains are made only over the edges and tips, from which a low soil pressure resistance in relation to soils constructed in this way results.

In contrast, raster electronic investigations show that by the addition of diabase in the densified material completely larger pores disappear and the edgy quartz grains of the loess completely in the Base mass of the sediment and the fine-grained components added ten are embedded. A significantly increased soil strength will be observed respects, which can probably be explained from the fact that by the fine grain and Basicity of the components blended into a hydrothermal re action of the soil components comes, whereby fine crystalline calcium silicate cathydrates are formed which have a strengthening effect.

From the above it follows that, surprisingly, by the Use of granular igneous rock, especially diabase, a chemical solidification that goes beyond the filling effect of the powder is reached.

With regard to the detailed composition of the here preferably in Diabase and basalts considered are referred to "Mineralo gische tables ", Hugo Strunz, 8th edition, Akademische Verlagsgesellschaft shaft Geest and Portig, 1982. The surfaces of the mineral bodies of these Individual minerals are in the soil to be solidified by the alkali solution obviously activated and activated. This makes him  possible that the mineral bodies of the soil (quartz, feldspars, clay mines ralaggregate) with the added minerals via calcium carbonate, Calcium silicate hydrate, calcium aluminate hydrate and calcium alumosi likate hydrate compounds a new, stable and intimate connection hen. In particular, those which have been activated by grinding are preferably added given mineral bodies in combination with silicon and aluminum ions involved.

As a further advantage of the procedure according to the invention compared to exclusive use of aggressive quicklime should be noted, that with comparable wind strength with a diabase addition only 20% ver blowing is compared to using an equal amount of brandy lime. This is particularly true when it comes to ground stabilization near residential development of importance.

For a practical soil stabilization can be provided, for example be that the proportion of calcium oxide or calcium hydroxide-containing mate rial is 0.1% to 30%.

The calcium hydroxide can also be used in liquid form or as a suspension be set and the batch accordingly as a whole as liquid or pasty suspension.

In this context, it is particularly useful that as a liquid Calcium hydroxide component is a waste product of acetylene manufacturing is used.  

The grain size of the diabase or basalt rock used is preferred wise in a band range from 0 to 0.8 mm.

For physical reasons, in addition to the fine-grained magma fish diabase or basalt rock a coarse-grained diabase or basalt rock stone can be provided in a grain size range of 1 to 32 mm.

In this respect it should be borne in mind that e.g. B. when using the advance screenings from quarries the upper grain a grain size of approx. 32 mm having.

In the following, the invention will be illustrated with the aid of a few exemplary embodiments explained here:

example 1

Floor fastening with diabase filler in the Loess Para brown soil with the aim of achieving a soil pressure resistance of 45 MN / m ² .

• - Soil compressive strength of the untreated soil: 11 ... 13 MN / m ² .
• - Soil pressure resistance of the untreated soil after four passes with the sheep foot roller: 25 MN / m ² .
• - Water content of the soil to be worked: 13%.

On the test field, 25 cm deep, according to the known technique of soil improvement with lime or cement, 24 kg of a diabase filler mixture with a ratio of diabase filler / quicklime of 4: 1 was introduced into the soil. After four passes with the sheep's foot roller, 53, 54 and 56 MN / m ^{2 were} measured.

The ratios EV1 / EV2 (see DiN 18134) were between 2.2 and 2.4. The evaluation using a scanning electron microscope showed that the loess par particles by calcium silicate hydrate (CSE), calcium aluminum hydrate (CAH), Calcium aluminosilicate hydrate (CASH) and calcium carbonate with the diabase filler particles are connected.

Example 2

Floor fastening with diabase filler with a loess / glue / silt sand mixture with the aim of achieving a soil pressure resistance of 45 MN / m ² .

• - Soil compressive strength of the untreated soil: 14 MkN / m ² .
• - Soil pressure resistance of the untreated soil after six passes with the sheep's foot roller: 27 MkN / m ² .
• - Water content of the soil to be treated: 17%.

On the test field, 25 cm deep, according to the technique of soil improvement with lime or cement, 60 kg of a diabase filler mixture with a ratio of diabase filler / quicklime of 4: 1 was placed in the soil. After six passes with the sheep's foot roller, 60 MkN / m ^{2 were} measured. The ratios EV1 / EV2 were between 2.0 and 2.3.

Example 3

In a laboratory test, loess / loam soil was treated with quicklime (mixture 1 ) and a 4: 1 diabas filler / lime mixture (mixture 2 ). The compaction properties of the filler mix are at least equivalent to those of the lime mix.

Example 4

Manufacture a compactible, further solidifying soil mass with the aim that this 25 cm high on a non-navigable soil carried soil mass together with the existing soil reaches a Druckfe strength of ≧ 45 MN / m ² .

• - Soil compressive strength of the untreated standing soil: 12 MN / m ² . Water content of the soil: 18%. Soil mixing component I, quarry screening not compactable.
• - water content 8%. 6% share of cohesive substances, 80% share of grain 2/45 mm soil mix component II, clayey / silty overburden.
• - Water content: 16%. 80% grain size, ≦ 0.06 mm.

The soil mixing components I and II were mixed in a ratio of 4: 1. Based on the proportion of soil mixing component II, 4% was one Diabase filler / quicklime mixture (mixing ratio 4: 1).

After six passes with the sheep's foot roller, a ground pressure strength of 60 MN / m ^{2 was} found. The EV2 / EV1 ratio was 1.9.

Claims (7)

1. Use of powdery, magmatic diabase or balsalt rock, in mixture with other mate, including silicate rialien for the consolidation of soils by on the Gö to be consolidated which the igneous rock powder applied and into the surface incorporated or placed in underground hollows and before is preferably solidified under pressure. 2. Batch for soil stabilization according to claim 1, comprising a Proportion of lime or calcium hydroxide containing material in addition to the mag matic diabase or basalt rock. 3. batch according to claim 2, characterized in that the proportion of Calcium oxide or material containing calcium hydroxide at 0.1% to 30% lies. 4. batch according to claim 1, characterized in that the Kalzi umhydroxid liquid or used as a suspension and the Ge total amount is formed as a liquid or pasty suspension. 5. batch according to claim 4, characterized in that as a liquid Calcium hydroxide component is a waste product of acetylene manufacturing is used. 6. batch according to claim 2, characterized in that the grain size ß of the igneous diabase or basalt rock used in one Band range from 0 to 0.8 mm.   7. batch according to claim 6, characterized in that in addition to the fine-grained igneous diabase or basalt rock made of physi a coarse-grained igneous rock in a grain size width from 1.0 to 32 mm is used.